If the purpose of comedy be to chastise human weaknesses I see no reason why any class of people should be exempt. This particular failing is one of the most damaging of all in its public consequences and we have seen that the theatre is a great medium of correction. The finest passages of a serious moral treatise are all too often less effective than those of a satire and for the majority of people there is no better form of reproof than depicting their faults to them: the most effective way of attacking vice is to expose it to public ridicule. People can put up with rebukes but they cannot bear being laughed at: they are prepared to be wicked but they dislike appearing ridiculous.

Preface, as translated by John Wood in The Misanthrope and Other Plays (Penguin, 1959), p. 101

Variant translation: People do not mind being wicked; but they object to being made ridiculous.

If everyone were clothed with integrity, If every heart were just, frank, kindly, The other virtues would be well-nigh useless, Since their chief purpose is to make us bear with patience The injustice of our fellows.

Act II, sc. vi. An apparent reference to Sigismund I, at the Council of Constance, 1414, said to a prelate who had objected to his Majesty's grammar, "Ego sum rex Romanus, et supra grammaticam" (I am the Roman emperor, and am above grammar).

Firstly, an inaccurate sourcing: in Act III, yes—but in Scene I, no: rather, in Scene V—HARPAGON, VALÈRE, MASTER JACQUES (see, e.g., the Project Gutenberg HTML version of the English translation: http://www.gutenberg.org/files/6923/6923-h/6923-h.htm). Secondly, a misattribution made clear by the Molière text—the character in the play, VAL, obviously points out that the quote refers to a "saying of one of the ancients" (and the quote is precisely written in quotation marks as well), in the full line of dialogue below:

Know, Master Jacques, you and people like you, that a table overloaded with eatables is a real cut-throat; that, to be the true friends of those we invite, frugality should reign throughout the repast we give, and that according to the saying of one of the ancients, "We must eat to live, and not live to eat."